Cylinder head for diesel engines



' May 15, 1951 J. B.ZIEGLER CYLINDER Hem-won Bissau-memes 2 Shasta-Sheet1 Filed July :5, 1950 I INVENTOR 4. 6! 68.

dost? 5 Z Patented May 15, 1951 UNITED STATES PATENT OFFICE 9 Claims.

This invention relates to the cylinder head of a Diesel engine and isdirected more particularly to a cylinder head embodying the invention ofmy Patent No. 2,503,186, dated April 4, 1950, and par ticularly the fuelinjection and precombustion features disclosed in that patent.

The primary object of this invention is to provide a cylinder head whichis mounted removably upon the engine block and which will permit theremoval of all valves from the head upon re moval of the head from theblock.

A further object is to prOVide an inexpensive and simple cylinder headconstruction which may be formed from a single casting.

A further object of this invention is to provide a construction by meansof which are injector valve associated with the engine cylinder may beoperated to open against high compression in the order of 500 pounds persquare inch, by the use of a force small in comparison to saidcompression.

A further object is to provide a device of this character in which therocker arm controlling the injector valve of the engine is acted upon ata point and in a manner, by a member responsive to the cylinderpressure, so that cylinder pressure is effective upon the rocker arm attwo substantially balanced points, and the force required to operate thevalve is much less than cylinder pressure.

Other objects will be apparent from the following specification.

In the drawing:

Fig. 1 is a top plan view of the device illustrated partiallydiagrammatically and with parts shown in cross-section.

Fig. 2 is a fragmentary vertical sectional View taken on line 2-2 ofFig. 1.

Fig. 3 is a fragmentary vertical sectional View taken on line 3-3 ofFig. 1.

Fig. 4 is a View similar to Fig. 3, but illustrating a modifiedembodiment of the invention.

Referring to the drawings which illustrate the preferred embodiment ofthe invention, the numeral l designates an engine block having acylinder bore l2 formed therein and adapted to receive a reciprocatingpiston M of any usual construction. A cylinder head I6 is mounted uponthe top of the engine block I 0, being bolted thereto by bolts (notshown) extending through the bolt holes !8. A suitable gasket 20 will beinterposed between the cylinder head and the engine block to effectivelyseal the parts.

The cylinder head [6 is provided with an injector chamber 22 open at itslower end into communication with the cylinder bore l2 of the engine andhaving a restricted opening at the center of its upper end to receiveand mount a valve guide member 24. This valve guide member slidablyreceives and guides the reciprocating stem 26 of an injector valvemember having an inner valve head portion 28 fitting snugly and slidablywithin the injector chamber and effectively sealed against the leakageof fluid therepast by piston rings 30. The intermediate portion of thevalve member at 32 is of restricted diameter. The outer end portion 34of the valve includes a conical valve portion 36 adapted to engage aseat 64 at the mouth of the chamber 22.

A chamber 40 .is formed within the cylinder head I6 adjacent to theinjector chamber 22 and in communication therewith. This chamber islaterally offset from the engine cylinder bore l2 as best illustrated inFig. 2. The chamber 40 has an air intake opening 4| adjacent its upperend and an opening receiving a guide 42. Slidable within the guide 42 isthe stem 44 of a valve head 46 adapted to engage a valve seat 48positioned intermediate the height of the cylinder head I 6. In otherwords, the seat 48 is spaced below the intake opening 4| and above thebottom surface of cylinder head. The valve stem 44 fixedly mounts aplate 50 spaced above the upper end of the valve guide 42, and a coilspring 52 bears at one end upon the cylinder head and at the other endon the plate 50 to normally urge the valve 46 to closed position. Inthis respect the construction is similar to the construction of themeans for normally positioning the injector valve 2836, the saidinjector valve similarly being provided with a washer or plate 54 uponits stem 26, and the projecting end of said stem being encircled by acoil spring 56 bearing at its lower end upon the cylinder head and atits upper end upon the plate 54.

The lower chamber portion 58, that is the portion of the chamber 40below the valve seat 48, is of a dimension to permit movement of thevalve head 46 between its closed position and a fully open position. Thechamber 58 constitutes a precombustion or fuel intake chamber andincludes a laterally projecting portion 60 which extends intocommunication with the injector chamber 22. The point of communicationof portion 60 with chamber 22 is located above the lower or valve seatportion 64 at the mouth of chamber 22 and at such a point as tocommunicate with the restricted intermediate portion 32 of the valvemember 28-36 when the latter is in its closed position.

An exhaust chamber 66 is formed in the cylinde head in communicationwith the cylinder bore I2 in spaced relation to the injector chamber 22and is provided at its mouth with an annular valve seat 68 against whichis adapted to bear the head II! of an exhaust valve member. The chamber66 communicates with an exhaust manifold at its upper end above thevalve seat 68 and has a restricted opening at its upper end in which ismounted a guide 12. The stem it of the valve I is slidable in the guide72. The valve stem 74 projects above the guide 12 exterior-1y of thecylinder head, and at its upper end mounts a cross-plate I6 againstwhichbears one end of a Spring I8 whose opposite end bears upon. the

cylinder head.

A transverse bore 80 is formed in the cylinder head off-set from thecylinder bore I2 and with its-axis substantially horizontal. A plug 82is mountedin the outer end of the bore 89 and serves asmeans forsecuring a fuel inlet conduit 7 ,84 to the :cylinder head fordischarge-of fluid into the chamber 80. The inner-end of the bore 86 is.of'reduced dimension at 86, and a reduced or small size port 83communicates with the .chamber portion 86 and with the precombustionchamber portion 58, 60., as best seen in Figs. 1 and .2. ,Another port90extends from the chamberportion 86'to open-at the valve seat 64, asbest seen in Figs. 1 and.2. 7 Within the bore 80 is positioned aretainer 92 having a chamber 94 receiving a spherical valve member 96.vided with a restricted port .98 at one end openinginto the chamberportion 86, and with a port ...I0..0. at its upper end. The constructionin this particular is preferably such that the valve element .96 mayseal the port .100 but is prevented from sealing the port 98, being inthis respect similar to the construction in my Patent No. 2,503,186aforesaid. The cylinder head I6 is provided with a chamber I92 locatedin spaced relation to the chami'bers 22 and 66, which chamber .is openat the lower end of the cylinder head into communication with theCylinder bore. At its upper end the cylinder head has a restrictedopening adapted to receive a valve guide sleeve I94 within which isslidable the shaft I05 of a plunger I98, preferably of cup shape asillustrated 'in Fig. 3, and also provided with a plurality of pistonrings II 0. The upper end of the valve stem I06 projecting from thevalve guide I04 has formed thereon a stop or plate H2, and a coil springII4 encircles the projecting end of the stem I06 bearing at its 7 upperend on the plate H2 and at its lower end upon the upper end of thecylinder head. The "chamber I02 may be closed at its inner end butpreferably will have a vent opening or passage therein. In thisembodiment it i contemplated that the chamber I02 shall be closed exceptfor the valve guide I94 and the valve stem I06 passing through theopening communicating.

one'po-int from a sealed to an open position The chambered member 92 ispro-' 2,552,657 t V l r r against a compressed charge, that is, a chargewithin the cylinder bore in the order of 500 pounds per square inch ormore. The means here illustrated for the purpose of actuating the valveconstitute a conventional push rod I22 which is actuated by a cam shaft(not shown) in the manner Well understood in the art, and which bears atits end portion I22, here illustrated as cup-shaped, against the head orknuckle I24 projecting fromthe rocker arm I26 journaled to rock upon theshaft I223. The rocker arm :26

M will be provided at one point thereof with a projection or bearingsurface I39 which engages the free end-of the valve stem I96, and with asecond projection or bearing portion I32 which bears against the freeend of the stem 26 of the valve 28:46.. The points of engagement of theshafts "26 and 106, respectively, with the rocker arm are preferablyspaced substantially equally from the shaft I28 upon which the rockerarm I26 is journaled, when the plunger M9 is ofthe same size or area asthe injector valve 28-4-36; Consequently, when there exists within thecylinder bore any charge under pressure, as during the compressionstroke of the operating Cycle of the quired to actuate the rocker arm 126 for the purpose of opening the valve 2836 against thepressurecontained within the engine cylinder :bore. It will be understood, ofcourse, that if the plunger I08 is of a different size or area thanvalve 2836, then the leverage action'can'be varied by changing thelocation of the rocker arm portions 1 30-I32 relative to the rockershaft to secure a balanced action and reduce theeiiort required tooperate the rock shaft.

The timing means for actuating the injector valve, the air .intake valveand the exhaust valve will be so arranged that during the compressionstroke the "injector valve will be held ajar' until the compressionwithin the cylinder 12 has --reached a predetermined value, for example,a

"The air entrains the liquid fuel which has entered that chamber anddischarges it through the passage 98 into the precombust'ion chamber 58,60. In this connection it Will be apparent that the line 84 will beconnected with a source of fuel, as by means of a low pressure fuelpump, so that the liquid fuel is supplied under a predetermined lowpressure into the chamber 86. The entrainment of the fuel in the airmixes the fuel and the air, and at the same time the pressure of the airdischarged from the cylinder through the passage acts against the valveelement 96 to shift the same to the position illustrated in Fig. 1, inwhich it seals the passage I00 as soon as the air pressure exceeds thepressure at which the fuel is supplied.

After the compression stroke has progressed to a point where apredetermined value of pressure has been reached, say 100 pounds persquare inch,

then the valve actuating mechanism serves to completely close theinjector valve 28--36 to seal the precombustion chamber at the valveseat 64, and the compression stroke of the piston engine continues untila predetermined time shortly before the engine connecting rod (notshown), which is operated by the piston, reaches its dead centerposition. At that time the injector valve 28-36 is substantially fullyopen, this action occurring against the compression within the cylinderwhich, as stated before, is commonly in the order of 500 pounds persquare inch. The highly compressed air within the cylinder will havebeen heated by its compression to an extent sufiicient to ignite thecharge contained within the injector nozzle and the precombustionchamber so that combustion will occur within the precombustion chambers58, 60 and within the portion of the chamber 22 surrounding the reducedportion 32 of the injector valve. This preignition will occur by thetime that the piston has reached dead center and the pre-ignition willforce the air-fuel mixture from the injector chamber into the cylinder,thereby causing ignition within the cylinder itself to generate powerrequired for the power stroke of the engine.

It will be noted that during the compression stroke after the injectorvalve 2836 has been fully sealed, the supply of fuel into theprecombustion chamber 58, 60 may continue by virtue of the fact that thepressure of the cylinder will not be effective within the chamber 86,and the comparatively low pressure existing Within the precombustionchamber Will be less than the pressure from the fuel pump, so that thevalve element 96 will be unseated. In this connection the valve chamberis so constructed that the valve element 96 is prevented from completelysealing the port 98, and stoppage of fuel supply by an inflow movementof the valve element 96 cannot occur. The operation of opening theinjector valve against the high pressure is made possible with theexertion of a force small compared to the force or reaction againstwhich the injector valve must operate to open. This result isaccomplished by virtue of the construction illustrated in Fig. 3 whichutilizes the application of the force within the cylinder to the rockerarm I26 by the stem I06 of the plunger I08 in opposition to the forceexerted by the charge within the cylinder upon the injector valve 28-36and transmitted to the rocker arm I26 by the valve stem 26. Since theforces on opposite sides of the rocker arm I 26 are substantially inbalance, the exertion of only a comparatively slight upward force on thepush rod I 20 is required to rock the arm I26 and shift the rod 26 toopen the injector valve 26-46. This feature thus simplifies both theconstruction and the operation of the device and increases theefficiency of the device by reducing the amount of force or effort whichis diverted from the work output of the engine for the purpose ofoperating the valves.

The embodiment of the invention illustrated in Fig. 4 differs from theconstruction illustrated in Fig. 1 primarily with reference to thenature of the means for reducing the effort or work required to actuatethe injector valve. This embodiment of the invention may in all otherrespects be the same as that illustrated in Figs.

end of the injector valve carries the cross-plate 54, a coil spring 56encircles the valve shank 26' and the valve guide 24' to normally urgethe valve stem upwardly toward valve setting position. The valve ischaracterized by the inner cylindrical portion 28' encircled by sealingor piston rings 30. The intermediate portion 32' of the valve is ofreduced dimension or crosssectional area, and the head 34' of the valveincludes the frusto conical portion 36'. It will be observed withrespect to this injector valve that it is of substantially the sameconstruction as that illustrated in Figs. 1 to 3 but difiers principallyby the absence of any direct connection with a mechanical actuator.

The Fig. 4 construction is further characterized by the chamber I02which receives the plunger I06 provided with the piston rings or otherseals 0'. The chamber I02 has an opening at its upper end receiving theguide member I04 which slidably receives the valve stem I06. In thisconstruction a coil spring I encircles the plunger stem I06 at theportion within the chamber I02, bearing at one end against the plungerI08 and at its opposite end against the guide I64. Consequently, thenormal action of the plunger under the influence of its spring I50 isinwardly with respect to the engine cylinder. The plunger rod I06extends exteriorly and passes through an opening in the rocker arm I26,being provided at its upper end with a head and retainer assembly unitI52 bearing upon the rocker arm I26. The rocker arm I26 pivots about theheader shaft or rocker shaft I28 to which one end of the rocker arm I26is connected. The opposite end of the rocker arm I26 carries thedepending knuckle head I24 adapted to be engaged by the cup-shaped headI22 upon the push rod I20.

The two chambers 22 and I02" are placed in communication with oneanother adjacent their inner ends by the cross-passage I54, and theportions of the chambers inwardly of the injector valve 28-36 and of theplunger I08, together with the cross connecting passage I54, iscompletely filled with a non-compressible liquid. The top surface of thecylinder head I2 is provided with a depression or oil sump I56 directlyabove the cross-passage I54, and a recess or bore I58 is formed in thecylinder head, the same having a restricted dimension outlet I60 at itslower end communicating with the cross-passage I54.

The shouldered or bottom portion of the chamber I58 adjacent therestricted outlet I60 is provided with ribs or shoulders I62. A ballvalve member I64 fits within the chamber I58, being adapted, when seatedupon the ribs I62, to permit the flow of liquid therepast. The upper endof the chamber I58 mounts an annular member I 66 having a central port I68. This port is adapted to be engaged and sealed by the valve elementI64. By reason of this construction it will be apparent that the partsI58, I68 constitute a check valve which permit the inflow of liquid fromthe oil sump I56 into the chambers 22, I02" and I54, but which preventsthe exhaust or discharge of oil or other liquid from said chambers. Ifthen a quantity of oil or other liquid is carried by the sump, it willbe apparent that during the operation of the engine the check valvearrangement HEB-I68 will insure constant complete filling of the chamberspace 22, I02, I54.

The operation of the device in this case is as follows: Whenever it isdesired to open the inthe parts.

amass"! 7 jector valve "28--36", the rocker arm, I26.- is rockedupwardly, i. e. clockwise as viewed in Fig. 4, by the push rod' I20.This action serves engine cylinder is: acting upon the bottom surface ofthe valve head 34' and of the plunger I 08', and, further, inasmuch as.the pressure acting oppositely upon these two members are equal, thereoccurs in this. construction a substantial equality of pressure. so thatthe force required to be exerted upon the push rod I20 and the rockershaft I26 is sufficient only to overcome the spring loading and thefriction of Stated differently, the pressure of the charge'actingupwardly against the plunger lll8 substantially counterbalances thepressure of the engine charge which resists downward movement of thevalve head 36. Consequently, it is not necessary that a high mechanicalforce be exerted for the purpose of opening the injector valve againstthe compressed charge. Therefore, it will be apparent that thisconstruction, which utilizes liquid or hydraulic pressure, a forcetransmission and pressure equalization, possesses substantially the sameadvantages as the embodiment above illustrated in which equalization ofoperating forces is secured through solely mechanical means. In otherwords, by this device applicant is taking advantage again of thepressure or of the charge within the engine cylinder to assist inperforming the work of opening the injector valve in a direction whichnormally would be resisted by that same engine charge.

While the constructions herein described and illustrated constitutepreferred embodiments of the invention, it will be understood that otherconstructions may be made within the scope of the appended claimswithout departing from the spirit of the invention.

I claim:

1. In a Diesel engine having a cylinder, a cylinder head having aninjector chamber adapted to communicate with said cylinder, an injectorvalve for controlling communication between said chamber and cylinderandadapted to be opened against high cylinder pressure, a valveactuator, and a member responsive to the pressure in the cylinder andacting in opposition to said valve to normally balance the pressurereaction exerted upon said actuator by aid valve.

2. In a Diesel engine having a cylinder, a cylinder head having aninjector chamber adapted to communicate with said cylinder, an injectorvalve for controlling communication between said chamber and cylinderand adapted to be opened against high cylinder pressure, a valveactuating rocker arm pivoted intermediate its ends about a fixed axis,said valve having a portion projecting from said cylinder head intoengagement with said arm, and a member responsive to the pressure in thecylinder and having a portion projecting from said cylinder head intoengagement with said arm spaced from the point of engagement of saidvalve portion and arm, said arm axis being spaced from and positionedbetween the aforesaid points' of engagement of said valve portion andpressure responsive member with said arm.

3. In a Diesel engine having a cylinder, a cylinder head having aninjector chamber adapted to communicate with said cylinder, an injectorvalve for controlling communication between said chamber and cylinderand adapted to be openedagainst high cylinder pressure, a valveactuating rocker arm pivoted intermediate its ends about a fixed axis,said valve having a portion projecting from said cylinder headintoengagement with said arm, and a member responsive to the pressure in thecylinder and having a portion projecting from said cylinder head intoengagement with said arm spaced from the point of engagement of saidvalve portion and arm, said arm axis being spaced from and positionedbetween the aforesaid points of engagement of said valve portion andpressure responsive member" with said arm, said valve and pressureresponsive member being of substantially equal area: and said points ofengagement being substantially'equally spaced from said arm' axis.

4. In a Diesel engine having a cylinder, a cylinder head having aninjector chamber adapted to communicate with said cylinder, an injectorvalve for controlling communication between said chamber and cylinderand adapted to be opened against high cylinder pressure, a valveactuating rocker arm pivoted intermediate its ends about a fixed axis,said valve having a portion projecting from said cylinder head intoengagement with said arm, and a member responsive to the pressure in thecylinder and having a portion projecting from said cylinder head intoengagement with said arm spaced from the point of engagement of saidvalve portion and arm, said arm axis being spaced from and positionedbetween the aforesaid points of engagement of said valve portion andpressure responsive member with said arm, the ratio of the spacing ofsaid points of engagement from said arm axis being substantiallyinversely-proportional to the ratio of the areas of said valve andpressure responsive member.

5. In a Diesel engine having a cylinder, a cylinder head having aninjector chamber adapted to communicate with said cylinder, an injectorvalve for controlling communication between said chamber and cylinderand adapted to be opened against high cylinder pressure, said cylinderhead having a second chamber and a passage connecting the inner ends ofsaid chambers, said valve including an inner sealing head portion, aplunger shiftable in and sealing said second chamber, said inner sealingvalve head portion and said plunger defining a sealed chamber filledwith liquid, and a rocker arm for shifting said plunger in its chamber.

6. In a Diesel engine having a cylinder, a cylinder head having aninjector chamber adapted to communicate with said cylinder, an injectorvalve for controlling communication between said chamber and cylinderand adapted to be opened against high cylinder pressure, said cylinderhead having a second chamber and a passage connectingthe inner end ofsaid chambers, said valve including an inner sealing head portion, aplunger shiftable in and sealing said second chamber, said inner sealingvalve head portion and said plunger defining a sealed cham,- ber filledwith liquid, and a rocker arm for shifting said plunger in its chamber,and means for replenishing liquid in said sealed chamber.

'7. In a Diesel engine having a cylinder, a cylinder head having aninjector chamber adapted to communicate with said cylinder, an

injector valve for controlling communication between said chamber andcylinder and adapted to be opened against high cylinder pressure, saidcylinder head having a second chamber and a passage connecting the innerends of said chambers, said valve including an inner sealing headportion, a plunger shiftable in and sealing said second chamber, saidinner sealing valve head portion and said plunger defining a sealedchamber filled with liquid, and a rocker arm for shifting said plungerin its chamber, said cylinder head having an oil sump positioned abovesaid sealed chamber, a passage connecting said sump and sealed chamber,and a check valve in said passage for admitting liquid into said sealedchamber.

8. In a Diesel engine having a cylinder, a cylinder head having aninjection chamber adapted to communicate with said cylinder at avalve-seat-defining mount portion, a precombustion chamber communicatingwith said injection chamber, an air intake passage communicating withsaid precombustion chamber, a fuel intake passage communicating withsaid precombustion chamber, and a passage branching from an intermediateportion of said fuel intake passage and open at said valve-seat-dafining injection chamber mouth, a valve for controlling air flow fromsaid air intake passage into said precombustion chamber, means forsupplying fuel to said fuel intake passage, and an injector valveincluding a sealing portion adapted to bear against said seat and aninner portion having a snug fit in said chamber.

97 In a Diesel engine having a cylinder, a cylinder head having aninjection chamber adapted to communicate with said cylinder at a 10va1ve-seat-defining mouth portion, a precombustion chamber communicatingwith saidinjection chamber, an air intake passage communicatin with saidprecombustion chamber, a fuel intake passage communicating with saidprecombustion chamber, and a passage branching from an intermediateportion of said fuel intake passage and open at said valve-seat-definJOSEPH B. ZIEGLER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,593,186 Ziegler Apr. 4, 1950FOREIGN PATENTS Number Country Date 5,690 Great Britain Mar. 7,. 1911

